1. Field of the Invention
The present invention relates to a video image coding and recording apparatus and a video image coding, recording and reproducing apparatus used for compression encoding a video signal to a coded bit stream, and also to a method of arranging the compression codes on a recording medium, and further to an error correction of reproduced signals.
2. Description of Prior Art
In recent years, with a development of a digital signal processing technique, various digital apparatuses have been developed. Recently, there has been proposed to develop a more compact size digital video recorder by recording digital video signals by compression encoding. As a method for compression encoding digital video signals, recently it has become popular to adopt a discrete cosine transformation (DCT) which is one of frequency conversion of the digital video signals into coding blocks such as JPEG (Joint Photographic Coding Experts Group) or MPEG (Moving Picture Coding Experts Group). According to the method, a digital video signal is divided into the coding blocks, the coding blocks are discrete cosine transformed to obtain coefficient data, and the coefficient data are compressed by variable length coding.
However, in a video image coding, recording and reproducing apparatus using the method as described above, when an error occurs in the data according to the recording and reproducing, it becomes impossible to decode variable length codes at and after an error occurring point. Further, even if a discontinued point of the variable length codes is detected and variable length decodes are refreshed by a refreshing code or the like, the variable length codes cannot be decoded for a section from the error occurring point to a refreshment point.
In a case as above, video images show a lack of several coding blocks on a video screen and this extends over several video screens. This has been a large problem in the compression encoding for the video image coding, recording and reproducing apparatus.